Field of the Invention
The present invention relates to a folding propeller for a boat, e.g., for a sailboat or a multihull yacht, where said folding propeller comprises a hub for directly or indirectly fastening at a driveshaft connected to a motor, where said folding propeller further comprises at least two individual blades, where each of said blades comprises a root arranged to pivot around a pivot pin at said hub in order to either be in a first and operative position, where the blades are pointing mainly in a radial direction, or in a second and inoperative position, where the blades are pointing mainly in an axial direction, where said hub comprises one or more cut outs for said blade roots and further comprises a first set of holes for installing said pivot pins and a second set of holes for installing said locking means for engagement with said pivot pins. The invention further comprises a method for installing and/or adjusting such a folding propeller.
Description of Related Art
It is well known that boats such as sailboats and multihull yachts use folding propellers in order to minimize drag, noise and wear when sailing without use of the auxiliary propelling means—a motor. Using a folding propeller will prevent that the propeller is rotated by the water and creates drag and noise when sailing and not using the motor, but further there is much less tendency for the propeller to get tangled up in fishing lines, rope and other articles that otherwise would accumulate on the propeller.
Another rather important issue when it comes to propellers for boats is corrosion and effectiveness. Galvanic corrosion can be limited by using sacrificial anodes that will be corroded instead of the propeller hub and blades. Another important subject is the effectiveness of the propeller, which can be compromised rather drastically due to fouling on the propeller parts. Until now the design of folding propellers did not address the problem with fouling very well. Further when the folding propeller has been used for some time and a little wear has occurred, there is no way of adjusting the individual blades neither in relation to the hub nor in relation to the other blades at the hub.
U.S. Pat. No. 5,403,217 describes a folding blade propeller for a power vessel, wherein the folding blade propeller comprises a hub for directly or indirectly mounting on a driving shaft, where the folding blade propeller further comprises at least two propeller blades, where each of the propeller blades comprises a base arranged to turn around each own pivot pin at the mentioned hub for in that way to be in either a first operative position, where the propeller blades are pointing in a mainly radial direction, or to be in another and inoperative position, where the propeller blades are pointing in a mainly axial direction, and where the mentioned hub comprises one or several cut outs for the mentioned bases and a first set of holes for inserting of the mentioned pivot pins.